Join Horizons – the team exploring and building AI-powered products that don’t have industry playbooks yet. As a Horizons Quality Engineer, you won’t just test features – you’ll define what “correct” means for AI systems that didn’t exist three months ago. This isn’t a traditional QE role with predefined test cases or stable requirements. You’ll operate in high ambiguity, where the product evolves weekly and the rules are still being written. Your impact will go beyond finding bugs – you’ll shape how we evaluate AI at Hostinger, define best practices, influence product decisions, and raise the quality bar for intelligent tools used by millions. This role is for someone who sees ambiguity as opportunity, not chaos – someone who doesn’t wait for documentation, but creates it, and who builds confidence in the future of our AI products. Key responsibilities include defining success criteria for AI-driven features where no industry standards exist, designing and executing testing strategies including exploratory and adversarial testing, developing evaluation frameworks to measure AI behavior such as accuracy, consistency, hallucination rate, edge-case handling, and stability. You will build and maintain testing datasets, validation pipelines, and experimentation frameworks while identifying patterns in AI behavior to develop intuition around its strengths, weaknesses, and risk areas. Acting as the voice of quality strategy, you will bridge the gap between what is built and how it is verified as truly good. Requirements include 4+ years of experience in software quality engineering, ideally with AI-powered products; strong critical thinking skills; experience in web testing and automation tools like Playwright, Cypress, or Selenium; programming skills (TypeScript is a plus); API testing and automation experience; database knowledge (MySQL or similar); ability to define and measure quality with meaningful metrics; strong curiosity about AI systems and technologies; and excellent communication skills in English. Preferred qualifications include hands-on experience testing LLM-based or AI-driven systems, knowledge of AI failure modes such as hallucinations and bias, and experience working in fast-paced experimental environments. Benefits include limitless learning opportunities with access to global conferences and mentoring, flexible work arrangements from offices in Kaunas and Vilnius or remote, comprehensive health insurance from day one, gym memberships, wellness programs, and a vibrant company culture with events and celebrations. The compensation starts from 4500 EUR gross per month, with upper range depending on experience and qualifications. Join Hostinger to grow fast in an innovative company helping millions succeed online with AI-powered tools.